Message Dialog library (#767)

* system/MsgDialog: types & basic text display

* system/MsgDialog: User message dialog

* system/MsgDialog: RAII for MsgDialog ui

* system/MsgDialog: Progress bar dialog

* system/MsgDialog: System message texts

* system/MsgDialog: copy all ui state to local memory

handles when game release memory before close
extracted all UI code to it's own file
use single window instead of creating new one every single dialogOpen

* system/MsgDialog: debug logging

src/imgui/imgui_std.h

@@ -0,0 +1,27 @@
+// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <imgui.h>
+
+#include "imgui_internal.h"
+
+namespace ImGui {
+
+inline void CentralizeWindow() {
+    const auto display_size = GetIO().DisplaySize;
+    SetNextWindowPos(display_size / 2.0f, ImGuiCond_Always, {0.5f});
+}
+
+inline void KeepNavHighlight() {
+    GetCurrentContext()->NavDisableHighlight = false;
+}
+
+inline void SetItemCurrentNavFocus() {
+    const auto ctx = GetCurrentContext();
+    SetFocusID(ctx->LastItemData.ID, ctx->CurrentWindow);
+    ctx->NavInitResult.Clear();
+}
+
+} // namespace ImGui